(1) Field of the Invention
The present invention relates to ostomy devices of the type adapted to be adhesively affixed to the skin surrounding the stoma and more particularly to such a device which includes external means for controlling evacuation by sealing the stoma while exerting only a minimum amount of sealing pressure.
Certain surgical procedures known as colostomy, ileostomy and urostomy result in an opening in the abdominal wall, called a stoma, which permits waste discharge from the interior of a body cavity. Since the patient has no control over the waste discharge, it is often necessary for the patients who have undergone these surgical procedures to utilize an ostomy device to protect the stoma and collect the waste material as it is discharged.
Over the years, ostomy devices of a variety of different types and constructions have been utilized. Various materials and adhesives have been developed to increase the utility and wareability of the devices.
(2) Description of Related Art
The basic ostomy device includes a collection receptacle or pouch connected to an adhesive coated faceplate which serves to mount the pouch to the body. The pouch includes first and second thin film walls which are sealed by heat welding or the like along the periphery. The pouch has an inlet opening designed to be aligned with the stoma and an outlet for emptying material from the pouch. In single piece devices, the pouch is permanently affixed to the adhesive coated faceplate. In two piece devices, the pouch is detachably mounted to the faceplate by coupling rings or the like, permitting the pouch to be replaced without removal of the faceplate each time.
The two piece device requires a means for releasably mounting the pouch to the faceplate. One particularly successful structure takes the form of a pair of annular or ring-like rigid or semi-rigid plastic parts, one in the form of an axially extending rib and the other in the form of a channel into which the rib may be removably received and frictionally engaged.
These ostomy devices collect waste as it is discharged but include no means for controlling when discharge takes place. One of the main objectives of these devices is to increase the freedom of mobility of the wearer and thus the wearer's ability to lead a normal life by participating in various activities. However, having discharge take place into the collection pouch in certain situations may cause embarrassment to the wearer because of the noise or smell or because of the increase in the size of the pouch.
Accordingly, it is desirable to control when evacuation takes place so that it does not occur at times which may cause embarrassment. Since the patient has no means to control waste discharge, it is desirable to provide a mechanical means by which waste discharge can be managed. One way to do this is to temporarily seal the stoma opening so as to prevent discharge when the seal is present. Once the seal is removed, evacuation of the bowel can take place.
However, an important concern in the management of stomas is to avoid exerting excess local pressure on the mucosal tissue. High local pressure can damage the stoma. Further, it can prevent blood flow to the tissue if the applied pressure exceeds capillary pressure. Thus, any acceptable evacuation control device must seal the stoma exerting harmful pressure on the stoma or surrounding tissue.